A Swelling Rage
by Melfice
Summary: It's the bruise on Stiles' arm, like the curve of fingers, that makes Derek see red.   DerekxStiles


**A/N: **Written for the kink meme prompt. Warnings for implied sexual assault.

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><p><strong>A Swelling Rage<strong>

Stiles is laughably easy to break.

He is made of bones that are brittle and do not bend, that break and shatter underneath pressure or tension or weight. There are soft muscles and tissue that can be torn, that cushion veins which are easily punctured and drained. He is covered in skin that is stretched thin, that rips and shreds like muslin to scissors. His body is a vessel easily overtaken, easily broken, and it heals slowly and tentatively and sometimes not at all.

There is strength of will in him, that can't be quantified or measured, but it is squandered in a surrounding weakness it cannot exist without.

There will be bruises forming on his back, in tired lines to match the indents in the door, bruises that will turn shades of purple and green and ache for days before they heal. The pressure will leave him sore, leave his muscles tired and aching. There are five sharp claws pressing incessantly against the curve of his hipbone, a twitch away from puncturing absurdly fragile layers of skin, and the press of those five fingers feels the movement of his veins, the solidity of the bones holding him together.

For all of his frailty, Stiles is surprisingly strong.

The hitch of a breath in his throat, surprise and anticipation and _excitement_, is louder in Derek's ears than it has any right to be. The beat of his heart is deafening, matches in time to the slow spreading flush across the back of his neck, and it sounds like war drums that are pounding their way up and down Derek's own veins.

Whatever breeze there had been, rolling in through the open window, may as well not exist. The room is sucked dry of its chill, pushed abruptly into stifling heat, and there is air in his lungs but Derek cannot_ breathe_. He feels a pulse underneath his hands that might as well be his own. There is fear there – fear from the uncertain, from the unknown, fear that has no right to exist; Derek can bruise and threaten, but it would be easier to sever a limb from his own body than cause permanent harm to the breakable boy in his hands.

It is the bruise on Stiles arm, shaped like the curve of fingers, that starts this all – that makes Derek see red. Stiles is the one who is fragile, who is easy to bend and to break, but it is Derek who feels as though he is being wrenched apart limb by precious limb. This mark may as well be seared into his own skin for how he feels it, for how it burns into his eyes, into his mind, and it's just a precursor to the worst of it all.

There is a smell on him Derek can't place, something foreign and masculine, something that is holding him tightly, clenching itself around his lungs, and it makes him choke with anger he is desperately trying to control.

"What the hell, man," Stiles manages, swallows thickly, and shifts underneath his grip without really trying to break away, "what are you – Derek, I didn't do anything – oh god, you've finally snapped, haven't you? Don't kill me – you don't even know, my dad would be alone and – oh my god-"

Derek's free hand slides over a warm and open mouth, tenses as though out of his control, and he growls, low, "_Shut up_, Stiles."

The boy's eyes are wide, hands at his sides even though they twitch with the urge to move, and his heart is _pounding_-

Stiles smells of himself, distinct and memorable, but also of grass and sweat – sweat that isn't his own, belongs to someone else – and Derek should have never come into this room, should have never come in through the window, should have let this feeling subside before he acted on it.

It's impossible to leave now, it's impossible to walk away with this eating away at him like it is, impossible to let it fester any further. He leans forward, hand flying from Stiles' mouth to grab his wrist, to pull his arm and its dark purple addition into view, and he manages to hiss, "Who did this?"

"W-what? What is your problem-"

Derek's grip tightens before he can stop himself. "_This_."

Stiles pulls away, tugs at his arm, and Derek lets him have it. He stays crowded against the door, held there by the pressure at his hip, and he looks away, looks confused and embarrassed and- "Nothing. It's old. You probably didn't notice it."

It's hard to bite back a snarl, hard to not snap at that, because Stiles is not stupid enough to think a lie will work. Because the bruise stands out against his pale skin like a beacon, like a taunt from someone Derek has never even _met, _and it is not old. It is fresh and dark and embraced by the scent of someone else's body, someone else's hands.

"Who," he says, slow and tenuous, "did this?"

Stiles purses his lips, expression steeled, determined, in a way that clearly broadcasts his reluctance to say anything further. He is looking away, strangely quiet for a moment in a way that seems normally incapable for him, and it makes something churn unpleasantly in Derek's stomach; it makes Derek want to find the man whose fingers fit that bruise, that makes him want to tear each and every one of those fingers out of their brittle sockets one by one.

The bruises on his knuckles are almost too faded to see, almost too faded to notice, but Derek _does_ notice. He notices the bruises there, like the impact of his fist into someone's face, and he notices the tear at the corner of his lip, the imprint of fingernails underneath those finger shaped bruises, and it is all so violently fresh that it feels like an insult.

"Does it matter?" Stiles asks, flustered and still not meeting his gaze. "It's not a big deal. I took care of it – I _can_ take care of myself, in case you haven't noticed how well I've been doing the last sixteen years. What do you care anyway? Only you're allowed to throw me around, is that it?"

It's that comment that does it. Derek feels his control like a single thread, being pulled tight across the room. His body feels like a live wire, tense and dangerous with barely contained anger, something indescribable boiling just underneath the surface. There's static in his head, in his ears, and he wonders if Stiles is thinking that – if he is thinking that Derek would fucking _dare_-

"If you said no," Derek says, gritting his teeth so hard his jaw aches, and his voice gets lost in a low growl that he can't control. Words make it worse, make it harder to keep himself focused. "I would _never_ fucking touch you."

Stiles' heartbeat is all he can hear in his ears, the sharp intake of his breath the only thing he feels for a long minute-

"No," Stiles manages, so tense it feels like he might snap in two, and that single word is like a punch to the face that pushes Derek's breath out of his lungs. He removes his fingers from Stiles in sudden, jerky motions, like they're made of stone and impossible to move. He takes one step backwards and he can't unclench his jaw when Stiles reaches out, almost desperately, and grabs the front of his shirt.

"I mean, no, no I won't say that," Stiles says in a rush, his free hand making a gesture that probably means something like _I'm socially awkward and don't know how to talk to people_, and he is looking to the side, unable to meet Derek's gaze, when he adds, "I didn't mean it like that, I know you wouldn't – I mean, I _trust you_. I – if it was you, if it was you then-"

And it's so close to being permission that Derek's body reacts almost out of his control. He surges forward, hands curling around Stiles' shoulders, pressing him back again. Stiles' mouth is open in surprise when he covers it with his own, when he presses back into him and takes before he has a chance to reconsider. He tastes familiar, like something Derek has been craving and been unable to find, and Derek licks his way into his mouth like it's somewhere he's allowed to be.

Stiles is tense against him, hands flattening against his shirt as if to stop him, but he doesn't attempt to push him away. He doesn't attempt to do _anything_ – doesn't move, doesn't breathe, does nothing but stand stock still against Derek, hands up but unmoving – and then, with a momentary twitch of hesitance, those hands curl around Derek's t-shirt like they're grounding him. Derek presses their hips together, low and hard, and there's a throaty moan from Stiles, his mouth parting further, and the string of Derek's self control stretches a little tighter, frays a little further. He pulls always, teeth catching on Stiles' lower lip, leaves his mouth wet and red, and he loosens his grip on the boy's shoulders enough to slide his hands down, down and up, underneath his shirt, to his pale, thin waist.

Stiles is hard against him, face flushed bright, eyes closed like he's too embarrassed to open them – doesn't open them until Derek squeezes against his waist, until he nuzzles briefly, strangely intimately, against the underside of his jaw.

He thinks he could find whoever had their hands on Stiles, thinks that he could find them by the last remnants of their scent on him, and it brings him a small measure of calm. Their circumstances are moot, their intentions irrelevant; he sees the imprint of their fingers on skin that doesn't belong to them, isn't theirs to touch, and he files it away in his head – for another time, a time when he doesn't have Stiles aroused and pliant against him.

"Then say yes," Derek says, tongue moving down Stiles' neck, a hint of claws brushing against his collarbone. "Stiles-" _please_, "say yes."

"Not you," Stiles says, voice surprisingly firm. "You don't have to ask."

And Derek is stronger, is faster, but he finds that, when Stiles pulls him closer, when it is Stiles' mouth that presses against his first, he is also incredibly weak.


End file.
